Obesity and Arthroplasty ... Again!

by Vince Vacketta, DPM

Beyond a surgeon’s experience and skill, patient selection is critical for the success of total ankle arthroplasty (TAA). While characteristics such as peripheral neuropathy or existing infections offer more objective guidance when counseling patients, the issue of obesity is more complex and increasingly significant due to the rising obesity epidemic. Two recent publications shed further light on this topic.

Ankle girth

While the body mass index (BMI) provides an objective measure of a patient’s overall size, other anthropometric variables can differ significantly among patients with similar BMI, such as the presence of “cankles.” Although large ankle circumference might be concerning when considering TAA, a recent study by Christie et al, presented at this year’s America College of Foot and Ankle Surgeons (ACFAS) conference may silence some fears.

The study, involving 100 TAA patients, showed an overall reduced risk of post-operative wound complications when using “anterior soft tissue depth” (ASTD) as a measure. Specifically, it was found that patients with an ASTD of 16 mm or less had a higher risk for post-operative wound dehiscence, which is a positive finding for patients with thicker ankles. 

Ethical considerations

The aforementioned study, as well as several studies assessing the effect of BMI on TAA, provide valuable objective data on TAA outcomes in obese patients. While there is generally an increased risk of complications and reduced TAA survivorship in obese individuals, ankle arthritis affects people of all shapes and sizes, and not everyone is an ideal candidate for arthrodesis. A recent article published by LaChance et al. in Journal of Bone and Joint Surgery offers a thought-provoking discussion, supported by literature, on the ethical considerations of nonmaleficence, beneficence, patient autonomy, and justice when considering TAA in obese patients. I encourage you to read more.